From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2ADD118A953 for ; Mon, 12 May 2025 00:50:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747011058; cv=none; b=G5492GY3xZxfICb2aH1a6bpJNh2Ek25yFZmuLoQnVmj4MlNIzGi2PITV6qAh/vAsKymTPxTzXXxM8buv4pfkFeXPB83fTbXL8sm3gK8u0/16Fsj4wk7EEnGcfaZDBnvSPpxVivbGVKq6jpjWZo+Gbbm8QOLRPFt6sITSGSBXe/o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747011058; c=relaxed/simple; bh=JjLQxzwBm9pnBSws3po0DSHrhiZEoS7XKZZ3aqwhqmg=; h=Date:To:From:Subject:Message-Id; b=QfAiii4ks36Nx1yBR7EtUKMpxs8ywJwUY4EFQkoDGrh7hOonZcynps9w8EdDdVajrrIyZxLov7HEB6+fd0LaLYjM1pI3SQnu0aVLc7scHcGJY/d3KCjkNGSKpqFL4UcsEDgiZeD8Va9Z0Rv9uyzQwwIHMwRHPY7Q31DJLAHG8Gk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=A8wLnL61; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="A8wLnL61" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 013DDC4CEE4; Mon, 12 May 2025 00:50:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1747011058; bh=JjLQxzwBm9pnBSws3po0DSHrhiZEoS7XKZZ3aqwhqmg=; h=Date:To:From:Subject:From; b=A8wLnL6186FBvx7os80uAw3nzXj/SsNdJcYNy5gvy/dntdsEURroAur2OkWtJRr81 X5PEhmaVYxFaEphow4Z1bPZCBkkYYbopgP5dr3Bo3RpkCkH9v/hghRupqeXxACBTCb D/ElA63L1b5qH9m2XT1XUrv/53LcjkRiJ/91Bo6U= Date: Sun, 11 May 2025 17:50:57 -0700 To: mm-commits@vger.kernel.org,willy@infradead.org,tongtiangen@huawei.com,peterz@infradead.org,olsajiri@gmail.com,oleg@redhat.com,namhyung@kernel.org,mingo@redhat.com,mhiramat@kernel.org,mark.rutland@arm.com,linux@armlinux.org.uk,kan.liang@linux.intel.com,irogers@google.com,andrii.nakryiko@gmail.com,alexander.shishkin@linux.intel.com,adrian.hunter@intel.com,acme@kernel.org,david@redhat.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] kernel-events-uprobes-pass-vma-instead-of-mm-to-remove_breakpoint.patch removed from -mm tree Message-Id: <20250512005058.013DDC4CEE4@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: kernel/events/uprobes: pass VMA instead of MM to remove_breakpoint() has been removed from the -mm tree. Its filename was kernel-events-uprobes-pass-vma-instead-of-mm-to-remove_breakpoint.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: David Hildenbrand Subject: kernel/events/uprobes: pass VMA instead of MM to remove_breakpoint() Date: Fri, 21 Mar 2025 12:37:11 +0100 Patch series "kernel/events/uprobes: uprobe_write_opcode() rewrite", v3. Currently, uprobe_write_opcode() implements COW-breaking manually, which is really far from ideal. Further, there is interest in supporting uprobes on hugetlb pages [1], and leaving at least the COW-breaking to the core will make this much easier. Also, I think the current code doesn't really handle some things properly (see patch #3) when replacing/zapping pages. Let's rewrite it, to leave COW-breaking to the fault handler, and handle registration/unregistration by temporarily unmapping the anonymous page, modifying it, and mapping it again. We still have to implement zapping of anonymous pages ourselves, unfortunately. We could look into not performing the temporary unmapping if we can perform the write atomically, which would likely also make adding hugetlb support a lot easier. But, limited (e.g., only PMD/PUD) hugetlb support could be added on top of this with some tweaking. Note that we now won't have to allocate another anonymous folio when unregistering (which will be beneficial for hugetlb as well), we can simply modify the already-mapped one from the registration (if any). When registering a uprobe, we'll first trigger a ptrace-like write fault to break COW, to then modify the already-mapped page. Briefly sanity tested with perf probes and with the bpf uprobes selftest. This patch (of 3): Pass VMA instead of MM to remove_breakpoint() and remove the "MM" argument from install_breakpoint(), because it can easily be derived from the VMA. Link: https://lkml.kernel.org/r/20250321113713.204682-1-david@redhat.com Link: https://lkml.kernel.org/r/20250321113713.204682-2-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: Oleg Nesterov Acked-by: Peter Zijlstra (Intel) Cc: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andrii Nakryiko Cc: Arnaldo Carvalho de Melo Cc: Ian Rogers Cc: Ingo Molnar Cc: Kan Liang Cc: Mark Rutland Cc: "Masami Hiramatsu (Google)" Cc: Matthew Wilcox (Oracle) Cc: Namhyung kim Cc: Russel King Cc: tongtiangen Signed-off-by: Andrew Morton --- kernel/events/uprobes.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) --- a/kernel/events/uprobes.c~kernel-events-uprobes-pass-vma-instead-of-mm-to-remove_breakpoint +++ a/kernel/events/uprobes.c @@ -1134,10 +1134,10 @@ static bool filter_chain(struct uprobe * return ret; } -static int -install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, - struct vm_area_struct *vma, unsigned long vaddr) +static int install_breakpoint(struct uprobe *uprobe, struct vm_area_struct *vma, + unsigned long vaddr) { + struct mm_struct *mm = vma->vm_mm; bool first_uprobe; int ret; @@ -1162,9 +1162,11 @@ install_breakpoint(struct uprobe *uprobe return ret; } -static int -remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr) +static int remove_breakpoint(struct uprobe *uprobe, struct vm_area_struct *vma, + unsigned long vaddr) { + struct mm_struct *mm = vma->vm_mm; + set_bit(MMF_RECALC_UPROBES, &mm->flags); return set_orig_insn(&uprobe->arch, mm, vaddr); } @@ -1296,10 +1298,10 @@ register_for_each_vma(struct uprobe *upr if (is_register) { /* consult only the "caller", new consumer. */ if (consumer_filter(new, mm)) - err = install_breakpoint(uprobe, mm, vma, info->vaddr); + err = install_breakpoint(uprobe, vma, info->vaddr); } else if (test_bit(MMF_HAS_UPROBES, &mm->flags)) { if (!filter_chain(uprobe, mm)) - err |= remove_breakpoint(uprobe, mm, info->vaddr); + err |= remove_breakpoint(uprobe, vma, info->vaddr); } unlock: @@ -1472,7 +1474,7 @@ static int unapply_uprobe(struct uprobe continue; vaddr = offset_to_vaddr(vma, uprobe->offset); - err |= remove_breakpoint(uprobe, mm, vaddr); + err |= remove_breakpoint(uprobe, vma, vaddr); } mmap_read_unlock(mm); @@ -1610,7 +1612,7 @@ int uprobe_mmap(struct vm_area_struct *v if (!fatal_signal_pending(current) && filter_chain(uprobe, vma->vm_mm)) { unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset); - install_breakpoint(uprobe, vma->vm_mm, vma, vaddr); + install_breakpoint(uprobe, vma, vaddr); } put_uprobe(uprobe); } _ Patches currently in -mm which might be from david@redhat.com are selftests-mm-add-simple-vm_pfnmap-tests-based-on-mmaping-dev-mem.patch